Effect of exhaustive swimming on the oxidative phosphorylation and the activity of some enzymes in rat liver mitochondria.

In liver mitochondria of control animals and of animals subjected to swimming for three hours experiments are made to determine the activities of rotenone-insensitive NAD.H-cytochrome c-oxireductase, succinate-cytochrome c-oxireductase, MDH, SDH, ATP-ase and cytochrome oxidase, as well as oxygen uptake, respiratory control index and ADP/O ratio upon oxidation of succinate and glutamate + malate. Decrease of the ADP/O ratio and of the respiratory control index, as well as increased ATP-ase activity, are established after swimming. The e--transport rate decreases. The activity of the remaining enzymes is unchanged. The activities of MDH, SDH, NAD.H-cytochrome c- and succinate-cytochrome c-oxireductases decrease 22 hours after exhaustive swimming. The activities of the cytochrome oxidase and the ATP-ase are unchanged compared with the controls. A single exhaustive loading results in changes in the capacity of phosphorylation in the liver mitochondria and the changes in the activities of the enzymes studied are established 22 hours later.